The method of joints focuses on the [[Pin Support|pin]] connections of a [[Truss|truss]] structure. By applying the [[Two-Dimensional Equilibrium Equations|force equilibrium]] equations and Newton's third law to each pin, the [[Force|forces]] acting upon the whole structure can be solved. The method of joints can be distilled into the following steps: 1. Solve the structures reaction forces. 2. Begin at a joint with: - At least one known load. - Two or fewer connected [[Two Force Members|members]]. 3. Use the equilibrium equations to solve the forces due to the members connected to the joint. Because members are two-force, the direction of forces must align with connecting members. 4. Balance forces on newly solved members by applying an equal and opposite force on the joint connected to the unsolved end of the member. 5. Repeat until all joints are solved for. ![[methJoint.png|center]] ![[JointEx.png|center|300]] It should always be remembered when using the method of joints, **the forces solved for act upon the pins**. Therefore, due to Newton’s third law, each pin will exert a force against neighboring members in an equal and opposite manner. As a consequence, arrows pointing outwards from members indicate that the member is in compression. Conversely,  arrows pointing inwards towards a member indicate the member is in tension. Again, this is because our free-body diagram using this method indicates the **forces that act upon the pins** of the structure. Finally, we can double-check our solution if we want. Check whether the [[Moment|moment]] at any point in the structure is zero and ensure that all forces cancel at every joint. ![[compten.png|center|500]]